Chemical mechanical polishing (hereinafter may be referred to as “CMP”) has attracted attention as a technique that can form a flat (planarized) surface when producing a semiconductor device. CMP is a technique that the surface (polishing surface) of a wafer on which devices and wires (interconnects) are formed, is polished chemically and mechanically with supplying a slurry to the surface of the chemical mechanical polishing pad, while sliding the polishing surface to come in contact with a polishing layer of a chemical mechanical polishing pad. It has been known that the removal rate, occurrence of scratches on the polishing surface, the in-plane uniformity of the polishing surface depends on the properties of the chemical mechanical polishing pad.
For example, JP-A-11-70463 discloses a chemical mechanical polishing pad that consists of a resin foam (e.g., polyurethane foam), and JP-A-2000-34416 discloses a chemical mechanical polishing pad prepared by dispersing water-soluble particles in a non-foaming matrix. Japanese Patent No. 3769581 discloses a technique that forms a recess in the polishing layer of the chemical mechanical polishing pad in order to achieve excellent polishing performance, and improves the fluidity of the slurry by improving the flatness of the inner side (e.g., side surface and bottom surface) of the recess.